hi im new and have a question on my mig straight off!

[samwatson]

Hello im sam from essex (england)
saturday i brought a second hand mig welder;
a SIP
migmate
turbo
105




was going alright, but after about 4hours use (on and off) i stoped to have a cup of tea, came back out to carry on welding, and the wire won't come out of the handle when the trigger is pulled. now i have checked and the wires is free. i took the side off to release the roller off the wire, to release all presure off the motor, and i pull the trigger in and still the motor won't turn.

so i took the (gear box so to speak) cogs apart and motor out, to see if someting jamed in there, and went to run the wotor with no load whatsoever and still nothing.
i then disconected the motor and put on a normal ouse hold 9volt battery and it funs fine both ways? so any advice on what i can be? something on the circuit bord i'm guessing. also when the trigger is pulled it theres a 'click' and a part on the circuite board incased in a small blue housing, moves like a latch it swing over by about 3-4 mm?

 

[rtbcomp]

Moved to SIP forum.

Sounds like the drive transistor on the circuit board may have blown. It'll be worth having a look at the board to see if there are any burnt out tracks or blown fuses.

 

[samwatson]

Moved to SIP forum.

Sounds like the drive transistor on the circuit board may have blown. It'll be worth having a look at the board to see if there are any burnt out tracks or blown fuses.

cheers fella will look tomorow, but what are tracks?

 

[Lawnmowerboy]

Hi there, where abouts are you in essex, may be able to take a look. I've had and attempted to repair many nackered mainly sip welders

will

 

[PTvor]

cheers fella will look tomorow, but what are tracks?

The board is a sheet of insulating material such as fibre glass. Holes are drilled through it through which the component leads are passed. The components are usually all on the top side. On the bottom of the board there are areas of thin copper to which the component leads are soldered and which connect the components together. These are the tracks or lands.

The lands are put on by an etching process, the bottom of the board starting as a single sheet of copper. It makes for mass production, among other advantages.

If a component has failed, it may have put enough current through one of the tracks to burn it away. In that case, when you repair the board, you can usually replace the track with a piece of wire.

Usually, it's fairly obvious when a track has burnt out, but there can be more subtle problems such a crack in the track which breaks the connection and isn't easy to see. Worse, since the gap in the track is small, it can conduct sometimes such as when the equipment is jolted, and then not work when the equipment is jolted again.

 

[shenion]

You can also check the power setting switches. If they get bumped, they may not be making a good contact. Sip's have been known for this problem.

 

[samwatson]

Hi there, where abouts are you in essex, may be able to take a look. I've had and attempted to repair many nackered mainly sip welders

will

rayleigh fella

 

[samwatson]

right had alook at the circuit board, and there doesn't seem any fuses that have blown can't find any fuses on the board. and can't see any broken tracks, no burn marks?

i had about a inch of welding wire hanging out the triger, so i thought i'd see if the weld still works, and turns out the weld doesn't work either now? any ideas? if not ill have to drop it into the tool menders...

 

[rtbcomp]

When you pull the trigger do you get a hefty clunk from the contactor.

It may be something simple like a faulty trigger or broken wire from the trigger.

 

[samwatson]

 

[samwatson]

When you pull the trigger do you get a hefty clunk from the contactor.

It may be something simple like a faulty trigger or broken wire from the trigger.

don't know what the contractor is. is it the blue rectangle bit on the circute board in the picture and this make a clunk! and a part inside the blue plastic case (on the board) moves by about 4 mm

any ideas?

 

[rtbcomp]

That's a relay, if that clicks with the trigger then the trigger circuit would be OK.

The contactor does the same job as a relay, but handles heavier current. They are normally used to switch the current to the transformer. I can't see anything in the photos resembling a contactor.

Did you try Shenion's suggestion to jiggle the power setting switches?

 

[PTvor]

There's a manual with a wiring diagram which probably covers this machine here.

http://www.mig-welding.co.uk/manuals.htm

Scroll down the page to the SIP/Cosmo section and click on the link which says

"SIP Manual (1.5Mb pdf) Works for most SIP welders up until about 2005"

A bit better than looking at it and wondering what all the parts are and how they are connected. If you are reasonably good with electrics or know someone who is, it should be possible to use the diagram to go through the welder with a meter and probably find the fault. Bad switches and diodes are easy to find with a meter.

If it's a fault on the board, it shouldn't be that hard to fix, but you'd need a soldering iron and the new parts, the transistor or whatever had died.

The fact that a relay clicks doesn't necessarily mean it works. The contacts could be moving but failing to connect because they are burned out or corroded.

 

[samwatson]

That's a relay, if that clicks with the trigger then the trigger circuit would be OK.

The contactor does the same job as a relay, but handles heavier current. They are normally used to switch the current to the transformer. I can't see anything in the photos resembling a contactor.

Did you try Shenion's suggestion to jiggle the power setting switches?

went and miss read that! i jiggled speed knob and not the power ones! ill have a look again in the morning! is it possible to open the relay and clean between the contacts? or that a bad idea?

 

[rtbcomp]

Sometimes you can prise the cover off relays. Cleaning contacts is a valid thing to do, there is/used to be a tool called a Diacrom Spatula to do the job. It was basically a doubled sided abrasive strip on a handle.

 

[samwatson]

Sometimes you can prise the cover off relays. Cleaning contacts is a valid thing to do, there is/used to be a tool called a Diacrom Spatula to do the job. It was basically a doubled sided abrasive strip on a handle.

ill try giving that a go if not ill have to learn to read the circuite diagram!

 

[PTvor]

is it possible to open the relay and clean between the contacts? or that a bad idea?

It depends on the relay. A lot of them are glued together. If that's so and view of the fact they only cost about £3 or £4 each new, it's hardly worth messing in my opinion.

Anyway, there's no reason to suspect the relay yet. I was just pointing out that the fact it clicks doesn't mean it works and supplies power to the transformer. You've got more detective work to do. There's no point jumping to conclusions and taking things to bits which you have no reason to believe are causing a problem, that is taking a lucky dip approach rather than work out what the problem is.

 

[samwatson]

You can also check the power setting switches. If they get bumped, they may not be making a good contact. Sip's have been known for this problem.

bang on fella!!!well done! did this thismorning flicking all the switches up and down etc then it all came back to life!! thanks verry much!

quick question though.... what actualy causes the bad contact?

 

[shenion]

It is just the type of switches they use. Most switches are spring-loaded to only be in one position or the other. The ones on the SIP seem to be able to be knocked into a middle position.

Glad to hear it works.

 

[BrokenBiker]

It was basically a doubled sided abrasive strip on a handle.

we do that sort of thing in work everynow and then, we just use some 1200 grit wet and dry on the end of a 1mm feeler guage, and then a very light blast from the airline to ensure all the loosend crap and stuff is removed, but anything heavier than a very light blast may remove some parts you need, as i found out the first time i tried it lol